Thermal insulation



Nov. 23, 1937. v H. A. KIESELBACH THERMAL INSULA'I ION Filed Feb. 25, 1935 N a b a w 1 K A W n H yhlnnanlunuaa.

Patented Nov. 23, 1937 UNITED STATES PATENT OFFICE 2,099,740 THERMAL INSULATION Henry A. Kieselbach, Montclair, N. J assignor to Johns-Manville Corporation, New York, N. Y., a. corporation of New York Application February 23, 1935, ScrialNo. 7,775

3 Claims. (Cl. 116-114) This invention relates to means for indicating The temperature indicators are disposed at, 1 the approximate temperature of an object protervals along the side of the heated object, from vided with an outer protective layer of thermal top to bottom, and contain an element 3 coninsulation and rendered thereby inaccessible to tacting with the surface of the heated object 5 observation by touch. and being preferably constituted of a thin flex- 5 It is frequently important to know what por- -ible metal disc adapted to conform closely with tion of an insulated object is heated or the apthe curved exterior surface of the object I, an proximate temperature of the object at various outer element such as a disc 4 of metal, and 2. positions inside the insulation. Thus, an observunion member 5, preferably also of metal, ex-

er may wish to note the condition as to tempera- [tending through the insulation and connecting 10 ture at various levels within a tank of heated oil the said two elements together. or in a domestic hot water tank. In the latter The elements 3 and 4 and the union member case, for instance, it is frequently desired'to know' 5 are constituted of material of high specific the approximate amount of heated water in the thermal conductance of the order of that of I tank, in order to prevent waste of fuel by heat-- metals, that is, of the heavy metals such as iron,

ing more water than necessary for a given purcopper, brass or the like, as distinguished from pose. When such a tank is thoroughly insulated the lower conductivity of less dense material such by an'outer covering, it is not feasible to observe as glass. by touch or by any other simple means the supply Conformance of the element 3 to the surface of hot water in the tank. of the object I and the close contact therewith 20 Previous devices that have been proposed for adapts the element 3 to receive heat readily the purpose of indicating the level or approxiand attain approximately'the temperature of the mate temperature of heated water or the like in surface of the object I. The high specific theran insulated tank have been complicated, subject mal conductance of the several elements of the 5 to considerable lag in time of showingatemperaindicating device adapts them'to conduct the ture condition prevailing in the tank, or adapted heat to the exposed element 4 and, also, adapts to permit substantial loss of heat through the this latter element to indicate to the touch the devices themselves. approximate temperature with greater certainty The present invention comprises means for than would be the case if the element 4 were of overcoming the stated disadvantages of previoussuch relatively poor conducting material as paper 30 ly used indicators, these means being described -or glass. below and illustrated in the attached drawing in Also, the union member 5 is of diameter that which is very small in comparison with the diameter of Fig. 1 shows a side view of a preferred emthe heat-gathering element 3. The smallness of bodiment of the invention, partly broken away diameter of the member 5 and its consequent 35 for clearness of illustration; relatively small surface minimize loss of heat Fig. 2 shows a sectional view on-an enlarged laterally from the said member. The area of scale, on line 22 of Fig. 1; cross section of the union member 5 is conse- Fig. 3 shows a sectional view, also on an enquently very small in proportion to the area of 40 larged scale, of a modified form of temperature the element 3 which contacts with the object I 40 indicator; and, also, in proportion to the area of the exposed Fig. 4 shows a side view of a portion of an element 4. insulation assembly having another modified As illustrated, the heat indicating means mayform of temperature indicator; and have roughly the shape and form of rivets, such Fig. 5 shows a sectional view on line 55 of as those of'copper, whichis a suitable material of 46 Fi 4. construction for the 'said means.

In the various figures likereference characters Preferably, the rivet-like indicators are made denote like p in two parts, adapted to be inserted through the There are shown an object I such as a vertically insulation from opposite sides and to give snug.

50 arranged cylindrical domestic hot water tank and contact at the place of union, so that flow oi. 50 an outer protective layer of insulation 2 placed heat between the two parts will be satisfactory. therearound. The insulation may be of any suit- Thus, the union member may contain male and able type, of which a plurality of composited female parts, as illustrated in Fig. 2, contacting sheets of asbes p per defining air spaces thercover substantial areas, so that heat flow from between is satisfactory. one part to the other is facilitated. 56

In the m dification shown in Fig. 3, the outer element 6 adapted to minimize loss of heat therefrom to the outside of the insulation I.

Thus, the element is of dished shape and coning device. This screw connection provides large surfaces of contact favoring the flow of heat through the union member. To facilitate the screwing together of these members, the portion 9 is suitably made independently tumable with respect to the exterior element 6, so that the element 6,-preferably saddle shaped to fit the curvature of the insulation, may be brought into conforming contact therewith and the portion 9 of the union member then turned by a suitable tool, to cause engagement of the thread with the portion ill of the union member.

in the modification shown in Figs. 4 and 5, a heat-gathering element ll is'incontact with the object insulated. A similar element I2 is exposed on the outside of the insulation and the union member I3 extends through the joint between adjacent portions ll and I5 of the insulation. If it is desired to avoid accidental displacement of the temperature indicator along the joint, the elements H and I! may be provided with means l6 and H, such as depressed points penetrating the insulation, to establish the position of the temperature indicator with reference thereto. They are of high specific thermal conductance as described.

The temperature indicator, parts II, II, and it, are suitably constructed of thin sheet metal, say number 28 gauge brass or the like.

The modification shown in Figs. 4 and 5 has special merit in that there is no through-penetration of the insulating material by any portion of the temperature indicator. The union mem- I I ber of this form of indicator lies in the joint.

With a tank provided with insulation containing the tangible temperature-indicating devices that are readily accessible, for being touched by the finger of an observer, as described, an observer may touch the various buttons or elements 4 or l2, arranged along the tank, and thus learn the approximate amount or temperature of heated liquid within the tank. At the same time, the small area of cross section of material,

, through which heat may flow through the indicating means,'minimizes loss of heat, the passage of which from the tank the insulation is intended to prevent. The indicating devices are very simple and relatively inexpensive. Finally,

the indicating means, being of small mass and therearound and means for indicating by finger touch the approximate temperature of the tank, the said means comprising an element in contact with the. tank, an element exposed on the outside of. the insulation and constituting a readily I accessible tangible temperature indicator, and a union member, of area of cross section very small in proportion to the area of either of the said two elements, connecting the said elements and the said elements and union member being each of high specific thermal conductance of the order of that of metals.

2. An assembly as described in claim 1, the element in contact with the said tank being flex-.

ible and conforming approximately to the exterior surface of the tank.

3. An assembly as described in claim 1, the said union member, being divided into two portions fitting snugly together over a substantial ,area thereof and eachof the said portions being integral with one of the said elements.

, HENRY A. KIESELB'ACH. 

